Phoenix Software International

January 18, 2012

Dear Falcon Customer,

The purpose of this notice is to alert you to a situation that could result in an outage in your environment.

The I/O driver used by the Falcon TP Monitor, first delivered in 2007 acquires its IOBE in private area storage for non-zHPF channel programs. This will lead to abend0C4s in IBM’s IOSVSSCH module for systems with IBM APAR OA37420 applied. On those systems, IOSVSSCH attempts to load the new IOBECTKN field (added by the APAR) while running in an SRB dispatched to another address space. The abend0C4 occurs because the IOBE is not in common storage. The outage occurs because an IPL is necessary to back out the IBM APAR.

For zHPF channel programs, the I/O driver is already acquiring the IOBE in common storage. Therefore, zHPF channel programs are not exposed to this problem.

APAR OA37420 closed on November 16, 2011. The PTFs became generally available on November 30, 2011. Because the APAR is marked HIPER, there is a good chance it will be installed ahead of other service on your system(s).

This issue is addressed by the following FALCON service:


With this service applied, the I/O driver will no longer set the IOBE address that is in private storage for non zHPF I/O, bypassing the problem.

No IPL is required after applying this service, but the Falcon product must be recycled after applying the service in order for the fix to take effect.

We hope this alert reaches you in time to prevent any inconvenience.


Phoenix Software International